Hi, BeJoi:
Congratulations on beginning your FSR treatments. Sounds familiar.
I underwent 26 FSR treatments last fall, 3 months after my retrosigmoid surgery. I don't know if I had the 'Trilogy System' (that name was never mentioned) but my neurosurgeon and a radiation oncologist he partnered with, carefully programmed the radiation beams to hit only the remaining tumor and avoid the facial/cranial nerves. I received very low 'doses' of radiation, according to the radiation doc. I do recall the 'moving bed' and the angles, as you mentioned. Unfortunately, my hearing on the 'AN side' (my left ear) was effectively gone before the surgery or radiation and so, preserving it was never an issue, even though both the surgery and radiation were the type to preserve hearing.
Thankfully, I suffered no side effects except one day of slight nausea, a week or so into the treatment program. It wasn't quite a 'pleasant experience'...more like a boring experience...as the 5-day-a-week, 20-minute treatments quickly became routine and I would sometimes come very close to dozing off. My FSR treatments were sensibly scheduled for early afternoon, as I made it clear that early mornings were a no-go, due to the fact that it was a 45-minute ride (one way) from my residence to the hospital and I wasn't getting up at 5 A.M. to do this if it wasn't absolutely necessary. It wasn't. My 2 P.M. appointments were very convenient and didn't seem to be a problem for the staff who administered the FSR. I suspect that I might have been a favorite patient because I was always on time, never complained about anything - including the tight-fitting face-mask I had to wear - and I always had a positive attitude, as this was a lot easier than surgery and was intended to kill the stupid tumor that had given me so much trouble.
Before I knew it, it was mid-October and the FSR episode was over. The radiation oncologist said I did very well. He was totally optimistic about the chances for the tumor going into necrosis. My last MRI showed signs of necrosis and my neurological exam responses showed a noticeable improvement from prior tests (Dec. 2006). I have an MRI scheduled for June 20th to determine if there is any shrinkage of the remaining tumor. I expect there will be. We'll see.
On the whole, I'm doing very well, a year past surgery and 8 months following FSR treatments. I trust you'll have a similar experience and I certainly hope you do. Like others, I look forward to reading about your experiences.
Jim